Geographical data in cohort/longitudinal studies

Zhiqiang Feng

University of Edinburgh

CLOSER workshop, 22 November, 2016

Acknowledgements

• Thanks for contribution from Jon Johnson from Centre for Longitudinal Studies and Gemma Seabrook, Rosie French, Jonathan Tebbett from the CLOSER team in UCL

Geographical data

• Geographical identifier• Information about the cohort members’ residential location

• Or other location, such as place of work, place of study

• The primary identifier is the address from which the other geographical identifiers can be derived. • Including administrative regions, postcode geography and grid references.

Cohort member

Household of Cohort member

Dwelling unit

Address

Grid references Postcode

Grid references

Higher level geographies

Relationship between residential address and geographical identifiers

Distances between one address to the postcode centroid in postcode IV4 7JX

© Crown Copyright. Ordnance Survey (Digimap Licence)

Statistic Distance (m)

Mean 30.1

Median 23.1

Standard deviation 37.2

min 0

Max 4029.3

Summary statistics for distances between addresses and their postcode centroid in Edinburgh

Statistic Distance (m)

Mean 195.6

Median 54.4

Standard deviation 517.9

Min 0

Max 23899.5

Summary statistics for distances between addresses and their postcode centroid in

Highland

Postcode centroids and address points

Geographical identifiers

• The most common type of geographical identifier is a code which denotes the area in which a person lives at a particular time.

• Postcode

• Grid reference,

• Census output area,

• Electoral ward

• Local authority

• Geographical region

Millennium Cohort Study (MCS)

• The most recent of Britain’s national longitudinal birth cohort studies

• 19,000 children

• Born in the UK in 2000-01

• Five sweeps, 9 months, 3, 5, 7 and 11 years old

Geographical identifiers MCS

• 1998 ward code

• Census statistics ward code 2001

• Lower Super Output Area 2001

• Middle Super Output Area 2001

• Output Area, 2001

• Local authority 2001

• Westminster Parliamentary Constituencies, 2001

Source: Jon Johnston, 2009, Geographical identifiers in MCS, CLSDavid Church: 2015 Millennium Cohort Study, CLSFor wave 5, 2011 census output areas, lower super output areas, middle super output areas, Westminster parliamentary constituencies 2011 also available

1970 British Cohort Study (BCS)

• 17,000 people in England, Scotland and Wales

• Born in a single week of 1970.

• Eight sweeps in addition to the birth survey, ages 5, 10, 16, 26, 30, 34, 38 and 42.

Source: Shepherd, P, 2012, Geographical Data and the CLS Cohort Studies, CLS

Address geocoding in BCS70

Source: Shepherd, P, 2012, Geographical Data and the CLS Cohort Studies, CLS

Geocoding of addresses of early sweeps

• The addresses from the 1970, 1975 and 1980 sweeps have not been digitised before.

• As part of the work package 6, the addresses from the 1970, 1975 and 1980 sweeps were digitised and geocoded to postcode or grid references.

• PAF and manual matching

1958 National Child Development Study (NCDS)

• Around 17,000 people in England, Scotland and Wales

• Born in a single week of 1958.

• The birth survey in 1958, plus nine further surveys of all cohort members at ages 7, 11, 16, 23, 33, 42, 46, 50 and 55

Geographical identifier, NCDS

Source: Shepherd, P, 2012, Geographical Data and the CLS Cohort Studies

Geographical identifiers, NCDS

• From sweep 6 (1991):• 1998 ward code

• Census statistics ward code 2001

• Lower Super Output Area 2001

• Middle Super Output Area 2001

• Output Area, 2001

• Local authority 2001

• Westminster Parliamentary Constituencies, 2001

Source: David Church: 2015 Geographical identifier, NCDS CLSFor wave 9, 2011 census output areas, lower super output areas, middle super output areas, westminster parliamentary constituencies 2011 also available

Understanding society

• 5 waves so far• 2009-10, 10-11, 11-12,12-13, 13-14

• Main sample

• Innovative panel

• Ethnicity sample

Understanding society• Local Authority District

• Westminster Parliamentary Constituencies

• Local Education Authorities

• Travel to Work Areas

• Strategic Health Authorities

• Primary Care Organisations

• Census Area Statistics Wards

• Census 2001 Middle Layer Super Output Areas

• Census 2011 Middle Layer Super Output Areas

• Census 2001 Lower Layer Super Output Areas

• Census 2011 Lower Layer Super Output Areas

• Grid references

Source: https://www.understandingsociety.ac.uk/about/data-linkage#part2

Geographical variables

• Derived from cohort studies

• Linked to census & administrative variables• Provided by cohort studies

• User generated

Population censusTopic 1931 1951 1961 1971 1981 1991 2001 2011

Education

Whether scholar or student

Age at which full-time education ceased

School level qualifications

Scientific and technical qualifications

Higher qualifications

GB

GB GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

Employment

Activity

Students of working age

Working full-time or part-time

Weekly hours worked

Employment status (employee, self-employed)

Industry

Address of business

Occupation

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB3

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB4

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB

GB: Great Britain; E: England; W: Wales; S: Scotland

Source: Norris & Mounsey 1985; Champion 1996; ONS 2004

Year Geography

Enumeration

district

Output area Ward Local authority

1951 GB

1961 Partly on demand GB GB

1971 GB GB GB

1981 GB GB GB

1991 E,W S GB GB

2001 GB GB GB

2011 GB GB GB

Census geography

Note: for Scotland pseudo postcode sectors are used instead of ward in 1981, 1991 and 2001 censuses.

Source: Denham & Rhind 1983; Coombes, M. 1995

Areal deprivation from censusDeprivation indicator Description Note

Unemployment % as total economically active 1931 onward

Overcrowding % households with over 1 person per room 1931 onwards

Renters % households socially or privately rented; 1961 onwards

No car % households with no car or van 1971 onwards

Low social class % in social class 4 (partly skilled) and 5

(unskilled)

1951, 1971 for males

Lacking higher education % of all persons lacking higher level

qualifications

1951: terminated education at age 20 or

over (most

likely age category at which degree

obtained;

1971: holding a degree or equivalent ;

2001: level 4 or 5 out of five

degree level qualification

Back casting deprivation indicators

• Experiment using the 1991 and 2001 census data

• Scotland as study area (N of 2001 OAs = 42604, N of district=32, N of 1991 OAs = 38254, N of district 56)

1991 district level data

2001 Output area to 1991 district lookup table

Re-distributing 1991 district level data onto 2001 output area level

Summing up 1991 data from the 2001 OA level onto bespoke geographies

Bespoke geography

Radius = 1 kilometre

Index of multiple deprivation

• Domains: • income; employment; health and disability; education, skills and training;

housing; crime, and geographical access to services

• IMD has been updated regularly

• Different methods for different countries

Payne, R. A., & Abel, G. A. (2012). UK indices of multiple deprivation-a way to make

comparisons across constituent countries easier. Health Statistics Quarterly, (53), 22.

Air pollution

• In 1961 the UK established the world's first co-ordinated national air pollution monitoring network, called the National Survey.

• Data on daily average concentrations of BS and SO2 from monitoring sites can be obtained from the national air quality archive (www.airquality.co.uk).

Air pollution

• The CHESS project (Chronic Health Effects on Smoke and Sulphur project, Imperial College), concentrations of BS and SO2 at 1962, 1971, 1981, and 1991 were estimated onto 1 km grids in alignment with the 10-yearly UK population census.

• Air pollution dispersion models were developed to estimate annual average population exposures to PM10 (particulate matter 10 um), PM25 (particulate matter 2.5 um), NO2 (nitrogen dioxide), SO2 (sulphur dioxide), CO (carbon monoxide) and O3 (ozone) in Britain for 1994 onwards (Murrells et al 2010; Stedman 2003).

Air pollution source

Pollutant AURN NAEI CHESS

PM25 2002-2011

PM10 1994-2011

Black smoke 1961*-2007 1962, 1971, 1981, 1991

CO 2001-2010

NO2 1994-2011

NOx 2001-2010

O3 1994-2011

SO2 1961*-2005 1994-2011 1962, 1971, 1981, 1991

* 1961 from April

AURN: Automatic Urban and Rural Monitoring Network

NAEI: National Atmospheric Emissions Inventory by AEACHESS: Chronic Health Effects on Smoke and Sulphur project

Climatic data

• Daily weather records from observing stations:

• MIDAS (Met Office Integrated Data Archive System) (http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_ukmo-midas). • from 1853

• free for academics.

• Alternatively the data can be requested from Met Office (http://www.metoffice.gov.uk/). • There is normally a charge from the Met Office for producing the data.

Climatic data

• The Met Office also maintains several time series calculated from the station records, • Met Office UK Climate series

• Met Office Hadley Centre series.

• 5 km grid points

• 25 km grid points

• regions (Perry & Hollis, 2005).